Mathematics Education Research Group of Australasia, Paper presented at the Annual Meeting of the Mathematics Education Research Group of Australasia (MERGA) (35th, Singapore, Jul 2-6, 2012)

One of the common tasks of inferential statistics is to compare two data sets. Long before formal statistical procedures, however, students can be encouraged to make comparisons between data sets and therefore build up intuitive statistical reasoning. Such tasks also give meaning to the data collection students may do. This study describes the answers given by beginning university students to tasks involving comparing data sets in graphical form, originally designed for students between Grades 3 to 9. The results show that whereas all the students had successfully completed either pre-tertiary mathematics or a bridging mathematics course many had similar difficulties to students of a younger age. In particular, they did not use a measure of centre or proportional reasoning when appropriate.